The present invention relates to high power, low resistance value resistors.
Normally such resistors are wire wound resistors which are made by winding a fine wire made from some resistance material around a ceramic cylinder with the ends of the wire welded to caps which are swaged to each end of the cylinder. Copper leads are normally welded to the caps and extend axially therefrom. Usually such wire wound resistors are then coated with some form of insulating material to protect the resistance wire.
The foregoing method of manufacturing a wire wound resistor requires numerous parts and is very labor intensive. The number of parts in such resistors is usually six (two end caps, two leads, one ceramic core, and one resistance wire). In addition to this, a coating of some sort must be provided.
Therefore, a primary object of the present invention is the provision of an improved power resistor which has high stability, relatively low resistance value, and a low temperature coefficient.
A further object of the present invention is the provision of a resistor which can be manufactured with a reduction in the amount of labor required.
A further object of the present invention is the provision of a resistor which has a reduced number of parts therein.
A further object of the present invention is the provision of a resistor which enables the production equipment to be fully automated and completely computer controlled.
A further object of the present invention is the provision of a process for making a resistor, which can utilize an in-line continuous process for manufacture.
A further object of the present invention is the provision of a resistor which can be manufactured at a greatly reduced cost.
A further object of the present invention is the provision of a resistor which can be automatically trimmed to very close tolerances with no additional labor costs.
A further object of the present invention is the provision of a resistor which is manufactured by a versatile production process so that a single type of material and production set-up can be used to make resistors with widely varying resistance value ranges.
A further object of the present invention is the provision of a process which automatically and naturally anneals and stabilizes the electrical characteristics of the resistors.
A further object of the present invention is the provision of a device which is economical to manufacture, durable and stable in use, and efficient in operation.